<span>Kennedy is using a rhetorical question to ask for support in making life better for everyone.</span>
I would say what type of work you do. It shows what the person is interested in and what the work they do and will be doing is going to look like. It also opens up information about who they are.
Susie's mom bought her SOMETHING at the grocery store.
Vague nouns are unspecific things that don't tell you exactly what something is!
More examples of vague nouns: something, things, stuff, etc.
The answer is C. to motivate Americans to strive for the development of their nation.
